The judging method of Italian coffee oil is determined by the thickness.

The thickness of ESPRESSO grease is a very complicated problem, which is much more complicated than the color of grease. The thickness of the grease is essential for making a real cappuccino and the popular coffee flower, so the rich and long-lasting grease can be said to be an important sign of high-quality ESPRESSO. The grease of ESPRESSO is not really a layer of "oil" floating on the surface of coffee, but is composed of delicate bubbles, so when we study the thickness of grease, we should not only look at how thick it is, but also observe how long it can last. The thickness of oil generally has a lot to do with the freshness of beans. If the beans are too fresh, the extracted oil will be very thick, but it will dissipate very quickly. We think that this kind of oil is too rough. Therefore, bean cultivation plays an irreplaceable role in the formation of oil. Only beans raised correctly can extract long-lasting oil. Although the fat is too thick is not necessarily a good thing, but if the oil is too thin, it must be a bad thing, generally due to: beans stored for too long or improper preservation; too little powder; grinding too coarse or too fine; extraction time is too long or too short; the flow rate is too large; improper filling pressure and other reasons. Generally speaking, I personally think that a serving (1 ounce) of ESPRESSO is a sign of high quality oil with a duration of at least 2 minutes.